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Is HRT Safe? Understanding the Breast Cancer Risk

By May 12, 2026July 8th, 2026Blogs, Breast Cancer Risk

“A balanced guide to menopause hormone therapy, breast cancer risk, and treatment decisions.”

Menopause symptoms can significantly affect an individual’s quality of life. Many women are concerned about the safety of hormone replacement therapy (HRT), particularly regarding the risk of breast cancer. The following reflects current evidence on the matter.

What is HRT?

Hormone Replacement Therapy (HRT) or Menopause Hormone Therapy (MHT) is a medication utilized to alleviate symptoms associated with menopause. As women age, menopause typically occurs as a natural transition at the conclusion of their reproductive phase, with the average age of onset being 51 years in Australia. Nevertheless, menopause may occur prematurely, prior to the age of 40, or be delayed into the 60s.

What is menopause?

A woman is regarded as having reached menopause when she has not experienced any menstrual bleeding for a period of 12 months. During this stage, the body secretes lower levels of the female sex hormone oestrogen and often decreased quantities of another hormone, progesterone.

Women may experience varying degrees of impact during menopause and as they continue to endure its effects. Usual symptoms include hot flushes, night sweats, fluctuations in mood and memory or concentration, vaginal dryness, diminished libido, sleep disturbances, and joint discomfort. Up to 25% of women report minimal or no menopausal symptoms. Approximately 50% of women encounter moderate symptoms, while as many as 25% suffer from severe symptoms attributable to menopause.

When is HRT prescribed?

Hormone Replacement Therapy (HRT) or Menopausal Hormone Therapy (MHT) is administered when menopausal symptoms become troublesome, with the objective of managing them and improving the patient’s quality of life. HRT alleviates menopausal symptoms through the replacement of oestrogen and, in some cases, progesterone. It is important to note that female hormones play a protective role against cardiovascular disease and against the reduction in bone density (osteoporosis).

Are there different types of HRT?

Yes, there are various types of hormone replacement therapy, with the two primary categories being:

  1. Oestrogen-only hormone replacement therapy (HRT) is employed in women who have undergone a hysterectomy (removal of the uterus).
  2. Combined hormone replacement therapy (HRT), which encompasses oestrogen and progesterone, is administered to women who retain their uterus. This approach is adopted because progesterone functions to safeguard the uterine lining against excessive thickening.

HRT can be administered in various forms, such as tablets, patches, gels, sprays, or vaginal preparations.

Does hormone replacement therapy (HRT) cause breast cancer?

Large research studies, including the Women’s Health Initiative, have looked closely at the link between hormone replacement therapy (HRT) and breast cancer. These studies help us understand how different types of HRT affect risk.

Which types of HRT affect breast cancer risk?

  1. Combined HRT (oestrogen and progesterone): This type of HRT is linked to a small increase in breast cancer risk, especially when used for more than three to five years.
  2. Oestrogen-only HRT: Most studies show little or no increase in breast cancer risk.
  3. Low-dose vaginal oestrogen: This does not increase breast cancer risk.

How big is the risk?

For most women, the increase in risk is small.

To give an example, out of 1,000 women aged 50–59 who do not use HRT, around 23 may develop breast cancer over five years. If 1,000 women of the same age use combined HRT for five years, there may be an additional four to eight cases.

Your doctor can help explain what this means for you personally and discuss your individual risk and treatment options.

What happens to the risk after stopping HRT?

The increased risk gradually reduces after stopping HRT. After about 5 years off treatment, the risk is close to baseline. The longer HRT is used, the longer the small increased risk may persist.

Can I take HRT if I have had breast cancer?

Generally, systemic HRT (tablets, patches, gels) is not recommended for women with a history of breast cancer.

However:

  • Low-dose vaginal oestrogen may sometimes be considered under specialist guidance.
  • Non-hormonal treatments are often recommended first.
  • Always discuss this carefully with your breast surgeon or oncologist.

Does HRT have benefits?

Yes. For many women, HRT:

  • Significantly improves quality of life
  • Protects against osteoporosis (bone thinning)
  • May reduce fracture risk
  • May improve sleep and mood

For women under 60 or within 10 years of menopause, the benefits often outweigh the risks.

Who should avoid HRT?

HRT may not be suitable if you have:

  • A history of breast cancer
  • Active liver disease
  • Uncontrolled high blood pressure
  • A history of blood clots (depending on the type of HRT)

Transdermal (patch or gel) forms may be safer for some women.

If I have a family history of breast cancer, can I take HRT?

Having a family history of breast cancer does not automatically mean that you cannot use HRT. Your doctor will carefully assess your individual situation, including how many relatives have been affected, their age at diagnosis, and whether there is any known genetic risk, such as a BRCA gene mutation. Based on this information, the decision about HRT is personalised and made together with you.

Should I be screened differently if I use HRT?

Women who use HRT should continue to attend their routine mammogram appointments and should promptly report any new breast lump or breast change/s to their doctor. HRT can make breast tissue slightly denser in some women, which may occasionally make mammograms harder to interpret, but regular screening remains important and effective.

What are alternatives to HRT?

If HRT is not suitable for you, there are several other options that may help manage menopausal symptoms. These include non-hormonal medications, such as certain antidepressants or gabapentin, which can reduce hot flushes and night sweats. Vaginal moisturisers or lubricants can help relieve vaginal dryness, while lifestyle measures such as regular exercise, maintaining a healthy weight, and reducing alcohol intake may also improve symptoms. Cognitive behavioural therapy can be helpful for managing sleep problems and hot flushes.

Key Take-Home Messages

  • HRT is effective for menopause symptoms.
  • Combined HRT slightly increases breast cancer risk.
  • The risk is small and reduces after stopping.
  • The decision to use HRT is individual and should be discussed with your doctor.
  • Quality of life is an important part of the decision.

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Bibliography

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The North American Menopause Society. The 2022 hormone therapy position statement of The North American
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Australasian Menopause Society. Breast cancer and menopause: Information sheet. Australasian Menopause Society;
updated 2025. Available at: https://www.menopause.org.au
Collaborative Group on Hormonal Factors in Breast Cancer. Type and timing of menopausal hormone therapy and
breast cancer risk: Individual participant meta-analysis of the worldwide epidemiological evidence. Lancet. 2019;394:1159–1168.
Women’s Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal
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Cancer Australia. Management of menopausal symptoms in women with a history of breast cancer. Clinical practice
guideline. Updated November 2024. Available at: https://www.canceraustralia.gov.au

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